/Engine/Plugins/Experimental/LandscapePatch/Source/LandscapePatch/Public/LandscapeTexturePatchPS.h
Amount of the patch edge to not apply in UV space. Generally set to 0.5/Dimensions to avoid applying the edge half-pixels.
typedef zzNextMemberIdInWeightmapToPatch zzMemberIdInEdgeUVDeadBorder